Furnace



' March 31, 1925.

W. DYRSSEN FURNACE Filed June 28, 1923 4 Sheets-Sheet 1 INVENTORTWa/demar D r'ssen.

ATT RNEY March 31. 1925.

W. DY RSSEN FURNACE Filed June 28. 1923 4 Sheets-Sheet 2 INVENTORVl/aemarfl BY rlim March 31. 1925. 1,531,649

W. DYRSSE N FURNACE Filed June 28, 192.5 4 Sheets-Shet 4 INVENTORATTORNEY Patented Mar. 31, 1925.

UNITED STATES WALDEMAR DYRSSECN, OF NEW YORK, N. Y.

FURFTACE.

Application filed June 28, 1823. Serial No. 648,254.

T all whom it may concern:-

Be it known that I, VVALDEMAR DYRSSEN,

i a citizen of theUnited. States, and resident of the city, county, andState of New York,

have invented certain new and useful 1111- provements in Furnaces, ofwhich the following is a specification.

This invention refers to open hearth and other furnaces havingregenerators for preheating the combustion air and to the method andmeans for reversing the direction of flow of air through theregenerators, but with the flame flowing constantly in the samedirection through the melting chamher. In an ordinary open hearthfurnace the combustion air and sometimes thefuel, as for instance in thecase of producer gas, is preheated in regenerators and at the reversalof the flow in the regenerator chainbers the flame is also reversed inthe melting chamber, so that at one period the flame enters the meltingchamber at the left hand end of the'furnace and the next period 1 at theright hand end.

It has been proposed before, to use unidirectional flame, that is, tohave the combustion air and fuel enter the melting chamber from-oneendonly at all times. The

flow of air through the regenerators as heretofore arranged 'Wasreversed by manipulating valves in the passages between the regeneratorsand the ends of the furnace. Such valves .are necessarily located wherethe Waste gases from the furnace and the combustion air are hottest.These valves do not stand up in practice except with the use of extremewater-cooling which, however, cools down the gases and the combustionair to such an extent that the proper flame temperature cannot bemaintained in thefurnace. On account of this disadvantage, theuni-directional flame .furnace has not been successfully used and is notused at the present time.

In my invention I haveno valves in the hot flue's between theregenerators and the melting chamber; either in the) waste gas passageorfin" the hot air passage. Instead of val-ves I provide means forcreating the necessarygpressure difference by'the use of nozzles,according to theinduced draft method. These nozzles can either functionin such a way that the flow of gases is obtained or they can function insuch away that the openings in the gas passages are,

filled with the gas introduced through the nozzle, creating a pressuredifference in the fines at this point, so thatno gases passthrough theflue. In other words, the induced draft acts as a shut off valve.

I have illustrated embodiments of the invention in the accompanyingdrawings in which Fig. 1 is a plan view of the furnace and associatedparts;

Fig. 2 is avertical section on line 22 of Fig. 1 through the meltingchamber and ends of the furnace;

Fig. 3 is a vertical section on line 3-3 of Fig. 1 through one of theregenerators of the same furnace;

Fig. 1 is a plan of a somewhat modified furnace; I Fig. 5 is a sectionon line 5-5 of Fig. 4.

Referring to Fig. 1 the furnace illustrated has the usual hearth 1, afront wall 2 with door openings 2 anda back wall 3 with the tappingspout 4.. The fuel and air are introduced at the right end 5 of thefurnace, and products of combustion are withdrawn at the left end 6. Inthis furnace, only the air is preheated and therefore only tworegenerators 7 and 8 are used. The 3 'upper' parts 9 of the regenerators7 and 8 communicate through Venturi shaped openings 10 and 11respectively with a common flue 12, having a port opening 13 at the end6 of the melting chamber. At points in the wall opposite the openings 10and '11 are nozzles 14 and 15 through which waste gases are suppliedunder pressure through pipes 16 and 17 by a fan 18 which-takes the gasesdirectly from the stack 19. The upper part 9 ofeach of the regeneratorsalso communicates through flues 20 and 21 respectively withVenturi-shap'ed openin s 22 a and 23 with; the vertical flue 24 at t:eilgburner end of the furnace. The air inlet flue to the melting chamberis inclined as indicated by 25 (Fig. 2'), at the point where the fuel isintroduced through burner 26. The fuel used is either tar, coke ovengas, powdered coal, fuel oil, naturalfgas or producer gas.

At points in the walls opposite'the Venturi openings 22 and 23, nozzles27 and 28 are mounted. 3 These nozzles are supplied with ease gasesunder pressure through pipes 29 and '30, from fan 18. The respectivelower part 31. of the regenerator cha n ber communicates by fiues32 and'33 re spectively with the stack 19. v Shut-01f valves 32 and '33 areplaced in-theee flues,

land-fan 35 supplies combustion air alter- 16, 17, 29 and 30" areprovided in thefour pipes 16,- 17 29 and 30 as shown.

In operation for one period the stack valve 32 in 'flue32 is closed andair is supplied from fan 35 through the pip 32. and flue 32. The airenters at the bottom of regenerator 7 and flows upward through thechecker bricks whichhave been previously heated and the air is thusheated when it reaches the upper part of the regenerator. From here the,air flows 1 through -flue 20, to opening 22 and flue 24 where it meetsthe fuel introduced through the burner 26. -The'flame is introduced inthe melting chamber above the hearth 1 and the waste gases are drawnthrough the port opening 13 into flue '12. From this flue the gases flowthrough the opening 11,=

into the upperpart of the regenerator 8 and the waste gases descendthrough the checker work, heating up same, and are finally withdrawnthrough flue 33 leading to the stack 19, the stack 'valve 33 being openat this time. There is, however, lower pressure in the waste gas flue12, than in the upper part of regenerator 7 The air in this part wouldtherefore have a tendencyto flow directly into flue 12 if there we're nomeans of preventing it from doing .so; In order to.prevent this flow,the valve 16 in pipe 16 is opened and waste gases in- 35. troducedthrough the nozzles '14 at. this point. .These waste gases create such acondition in the 'Venturiport 10 that a pressure difference will existbetween the regenerator or right hand side and the 'waste'gas flue sideor left hand of this opening. If the quantity and the pressure of thegases introduced at 14 is proper, there will be no flow of air or wastegases through tityof waste gases introducedthrough the nozzle 14 willpass off through flue 12, into regenerator 8, with the waste gasescomingfrom the melting chamber;

In a similar ,way there exists a pressure difleren'ce between flues 24and 21, and waste gases under pressure are introduced at 28, in order toprevent" flow of, air

through opening 23, in the same manner as described in opening 10. Thereis no need at this time of a flow of waste ases through the nozzles at27 and 15. T e waste gas ets that are used as a means of shutting offopenings 10 and 23, cool down the waste gases to'a certain extent beforethey enter the checker-work in regenerator 8. How i ever, the coolingdown will not be sutficient r to interfere with the proper heating ofthe checker-work in the regenerators which pre- 7 heat the air to thedesired temperature i When the flow of air and waste gas opening 10, andthe relatively small quan through the regenerators: is rev sed, thestack valve 32 in flue 32 is. open d and the valve 33* in flue 33 closedand valve 36 is shifted to divert the air from the fan into flue 33. Thevalves 16 and 30 in pipes 16 and 30 respectively are closedand in themelting chamber thus it is clear,

that the flame and gases flow constantly 'in the same direction throughthe ,melting chamber.

Referring to the modified arrangement showlr rn Figs. 4 and 5, theoutlet 39 from the melting chamber is Venturi-shaped and of oblong formas indicated. There. is an oblong nozzle 40 in the roof above theopening 39 through which waste gases under pressure are introduced.Opening 39 communicates with a flue 41 which communicates with the upperparts of regenerators 42 and 43. The other end of the upper part of eachof the regenerators 42 and 43 communicates by a flue 44, with the burnerend of the furnace. ed in Fig. 5 is suitable for producer'gas comingdirectly from the producers. The producer gas comes through pipe 45,provided with a regulating valve 46, and is introduced. into the burnerthrough flue 47. The lower partslof the regenerato'rs communicate withthe stack, not shown, by flues 48 and 49, in substantially the same waythe flues 32 and 33 are connected as explained with reference to Fig. 1;and the combus tion air is supplied to either flue 48 or 49 in a similarway, as describedwith reference to that figure.

In operation of the arrangement shown in Figs. 4 and 5, the stack valvein flue 48 is closed and combustion air is introduced into this flue.The air is preheated in regenerator 42, and flows to the burner.

through flue 44. The waste gases are withdrawn through the opening 39and flue41 The burner 50 indicat- I to regenerator 43, and passalternately to the stack through flue 49. There is, however, a pressuredifference between the upper parts of regenerator 42 and flife 41 sothat the combustion air would tend to pass directly into flue 41 if thispressure diifen ence was not. eliminated. In the same way air would passfrom the upper part of regenerator 42' through flue 44 to regenerator 43and to the stack, if, the pressure 'diflerg ence was not eliminated.'The elimination of this pressure difference is accomplished by blowinga jet of waste gas at a fairly high pressure from the nozzle 40 into theVenturi port 39.and the pressure difference is creat-- ed between themelting chamber and flue 41. If the pressureof the waste gases throughnozzle 40 is properly regulated, the 1 pressure .in flue 41 and in theupper part of the checker chamber 42 willbe exactly the same and therewill be no flow of air or gas through the opening 42 between 42 and 41.The opening 42 between'the regenerator 42 and flue 44 and theregenerator 43 and flue 41 respectively are of such area that the lossof pressure of the air and, gases passing through these openings is thesame, hence there will be no pressure difi'erencebetween fiue 44 andre-.

generator 43 and no air will pass this way to the, regenerator 43. Thedesired flow of air and waste gas is therefore obtained by the use of asingle nozzle which is pull-.

ing the waste gases from the melting chamber at all times. The reversalof flow of the gases through the regenerators is accomplished by simplyreversing the stack valves and the flow of combustion air from the fan.I

Instead of using the waste gases under pressure to create the necessarypressure differences in the system, hot air can also be used and variousother instrumentalities parting from the invention and combinations thanthose indicated in f the drawings and described herein can be used toperform the functions set forth without departing from the invention adefined in the appended claims' The gases used to create the necessarypressure differences can be introduced at other locations than thoseshown. andgases other than waste gas can be used. For example, eithercold or hot air can be introduced in the flue 44 between theregenerators and the burners or fuel gas can be introduced underpressure through the burners themselves. I

In the foregoing description, I have referred to the furnace as an openhearth fur- I nace, and have described the method with certainreferences to passing the flame or gases through the'melting chamber. Itis to be-under-stood, however,-that my invention is applicable to otherfurnaces in which nomelting takes place,'such as furnaces for heatingblooms, billets and thelike. -Thc term open hearth furnace as used inthe claims is intended to cover'such other furnaces,rand the term,melti'ng chamber is 1n.-.

tended to cover also .a heating chamber-in which no melting necessarilytakes place;

. Though I have described with great pan ticularity' the steps ofqmyimproved-method aifd details-of the apparatus for embodying theinvention,.it'- is not to be construed that I am limited thereby aschanges maybe made by thoseskilled inthe art. without deas defined inthe appended claims. 1 v

lVhat I claim is: 1. The method of controlling communication between themelting chamber of ametallurgicalfurnace and a regenerator through aport WhlCh is always open, which gmeltin g chamber consists in directinga jet of gas toward the open port to practically or substantially 3. Incombination with a furnace, a pair of regenerators, means for supplyingai-r thereto, a flue connectmg the regenerators,.

normally openports connecting said flue with each of said regenera'tors,normally open ports connecting each regenerator with the furnace andmeans for introducing a jet of gas toward certain of said ports toalternately control the circulation of air through one of saidregenerators to the fur nace and the passage of waste gases from thefurnace. j

4. In I combination with an open hearth furnace, "a pair ofregenerators, passages which are always open connecting the fur nacewith said regenerators, and means for introducing jets of gas to controlthe circu lation of combustion air and waste gas through said passages,the regenerators and the furnace.

5. In combination with an open hearth furnace and: regeneratorscommunicating therewith, means for causing the flame to pass constantlythrough the melting chamber of the furnace in the same directioncomprisingmeans for alternately-supply ing air to each regenerator,flues connecting the regenerators with the furnace atone end, ports atthe opposite end of the furnace communicating with said regenerators andmeans for directing jets of gas so as to permit the flow of the air andwaste gases through certain of said ports and flues and prevent theflues. i

furnace, pair of air regenerators, a flue connecting said regenerators,aport leading from said fine tothe melting-chamber of v the furnace,ports connecting said flue with I each of said regenerator-s, otherports'conflow through other ports and -6. In combination with an" openhearthnecting the-regenerators with the fuel inletv end of the meltingchamber, means for. alter- 'nately supplylngairjto each of saidregenerators and means for directing jets ofwaste' gas toward certain ofsaid ports soas to* a'lternatelyjpermit the I air to pass through oneofsaid regene'ratorsl to .the {melting erator. a 1

7. In combination with an openv hearth furnace, a'pa1r of regenerators'and :means,

chamber and the waste gas to passfron the through the other regennace inthe same direction withoutthe use 1 of valves in the ports leadingthereto, comprising flues for alternately supplying air and withdrawingwaste gases from the regenerators, a flue connecting the regenerators, avport at the outflow end of the melting chamber connected with saidflue, Ve-nturi shaped ports connecting each of the regenerators withsaid flue, Ventu-ri shaped ports connecting the regenerators with thefuel inlet end of the melting chamber, nozzles opposite each of saidVenturi shaped ports, means for discharging a fluid through said nozzlesand Valves for cutting off the supply of fluid to certain of saidnozzles.

8. In combination with an open hearth furnace, a pair of regenerators, aplurality of Venturi shaped ports through which the combustion airandwaste gases pass respectively to and from the furnace, and meansassociated with each of said ports for directing a jet of fluid towardcertain selected ports so as to determine which portsthe air and wastegas will traverse.

9. The method of controlling communication between a chamber in afurnace and a regenerator through a port which is'always open, whichconsists in directing a jet of munication between the chamber and theregenerator through said port.

10; .In combination with a furnace and the 'regenerators thereof, meansfor utilizing fluid jets at diflerent locations to exert ust sufficientpressure to control the circulation of the combustion air and waste gasthrough.

the regenerators and the furnace without theuse of valves in the flueswhich said combustion air and waste gas traverse.

11. In combination with auni-diredtional furnace and the regeneratorscommunicatmg therewith, means causing the combustion.

gases to pass constantly through the melting chamber of the furnace inthe same 'direcmunicating with passages leading to said regenerators,and means for creating a' pressure difference between certain ports soask to cause the flow of air and waste gas through certain of "saidports and'flues and preventthe flow through other ports and flues,without the use of valves located in the ports and flues which the gasand airtrav'erse. v 1 v p In witness whereof, I have hereunto signed myname.

WALDEMAR Dress-EN;

